Wood-bending machine.



W. A. KNILANSL I 'woon BBNDING MACHINE. APPLIUATIOK FILED AUG. 6, 1910;

977,804. Patented Dec. 6, 1910.

wwwegg w. A. KNILANS. WOOD BBNDING MACHINE. APPLICATION IIIJ'ED AUG. 6, 1910.

977,804. Patented Dec. 6,1910.

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WILLIAM A. KNILANS, OF SHEBOYGAN, WISCONSIN, ASSIGNOR T0 CROCKER CHAIR COMPANY, OF SHEBOYGAN, WISCONSIN.

WOOD-BENDING MACHINE.

Specification of Letters Patent.

Patented Dec. 6, 1910.

To all whom it may concern:

Be it known that 1, WILLIAM A. KNILANS, a citizen of the United States, and resident of Sheboygan, in the county of Sheboygan and State of Wisconsin, have invented certain new and useful Improvements in Wood- Bending Machines; and I do hereby declare that the following is a full, clear, and exact description thereof.

The object of my invention is to provide a simple, economical and efiicient wood bending machine, the machine being so constructed and arranged that the bending is effected by a gradual deflection of the stock fromone end, whereby the desired shape is obtained. This result is had through the closing up of jaw-like forms that are in fulcrum connection, which forms are cast with cored chambers for the admission of steam, whereby the green stock is bent, dried and seasoned at the same time as is usual with machines of the general character to which my invention pertains.

Heretofore it has been common practice to provide bending machines with a series of male and female reciprocative forms be tween which the stock is inserted, these forms being arranged to close up in a straight line to a nested position under power, whereby the straight stock is bent by pressure applied to its center by the male die, while the ends of the stock are supported by the female die. Thus in this type of machine the wood fiber of the stock is abruptly broken in one place to effect the desired bending and the material is consequently weakened or broken at the point of bending and when used in manufacture the contour desired to be preserved is more or less liable to be unsymmetrical. With my improved method the aforesaid objectionable result is entirely overcome due to the fact that one end of the material is initially held between the forms at their fulcrum points, the forms being thereafter closed to produce gradual bend desired in a rolling manner, whereby said bending stress is distributed uniformly throughout the entire length of the stock.

With the above object in view the invention consists in certain peculiarities of construction and combination of parts to be fully set forth hereinafter with reference to the accompanying drawings and subsequently claimed.

In the drawings Figure 1 represents a side elevation of a wood bending machine embodying the features of my invention, the machine. being shown in its closed position with a series of bent wood strips under compression between the male and female die faces of a series of forms; Fig. 2, a sectional elevation of the machine in its open position illustrating wood strips or stock inserted between the forms preparatory to being put under compression, the forms being broken away and in section to more clearly illustrate structural features; Fig. 3, a detail sectional plan view of a portion of the machine, the section being indicated by line 33 of Fig. 1, and Fig. t, a detail end v1ew of a pair of the forms illustrating their hinge or fulcrum connection:

Referring by characters to the drawings, 1 represents a bed from which extends two sets of tie-rods 2, the tie-rods being provided for the support of a fixed'form 3, which form is secured to said tie-rods by ears 4 and retaining nuts 5 in screw-threaded con nection with said tie-rods. Form 3 is hollow, as shown, to constitute a steam chamher, into which chamber steam is admitted and exhausted through apertures 6, 6 to which apertures are fitted suitable pipes not shown. The lower or die face of this form is shown as being convex, but itis understood that the contour thereof may be varied to suit the work required. A second form 3 is fulcrumed to the form 3 at one end by means of a hinge connection, the knuckle member 7 of which is secured to form 3, while the pintle member 8 is secured to form 3. The upper face of the form 3 constitutes the male member that operates in conjunction with the fixed form 3, while the lower face of said form 3 constitutes a female member which co-acts with the male face of a third form 3", it being understood that forms 3 and 3" are also provided with steam chambers having inlet and exhaust apertures 6, G similar to those previously mentioned in connection with the fixed form 3, with the exception that the two last mentioned forms being movable, are necessarily provided with flexible steam pipe fittings in connection with their inlet and exhaust openings, which fittings form no part of my invention and are therefore not illustrated.

The free end of form 3* is provided with a knuckle member 7 having a slotted extension 9 that is adapted to receive the pintle 8 of a hinged member that is secured to the adjacent end of the form 3 The free end of the form 3*, in turn, is connected to a reciprocative steam chambered form 3 by means of a knuckle member 7 and pintle member 8 which are similar in construction to those previously mentioned in connection with the first and second forms, the reciprocative form being also provided with steam inlet and exhaust apertures like those in connection with the latter. The form 3" has extending therefrom guide wingslO that engage the tie-rods 2 and thus serve to hold said form against side play. Power is applied to the form 3 through a piston 11 that is reciprocatively mounted within a hydraulic cylinder 12 in the usual manner.

From the foregoing description it will be seen that the intermediate forms are in fulcrum connection with the first and last forms 3, 3 respectively, the opposite ends of said intermediate forms being in fulcrum connection with each other, whereby they constitute toggles that are adapted to open or close when power is applied, there being practically no variation in width between the forms at their fulcrum points. Thus, as shown in Fig. 2, when the machine is open the stock A that is to be bent can readily be inserted between the forms at their fulcrum points, said stock being gagecl. and arranged to abut lateral guide strips 13 that are secured to the ends of forms 8, 3 and 3 these forms being the movable ones of the series.

hen the machine is in its open position it is necessary to provide means for limiting the swing of the form 3 in order that the lower forms may assume their proportionate open positions. The mechanism for accomplishing this result consists, as shown in Fig. 1, of a slotted strap 14 that is secured to form 3, there being a stud 15 carried by the fixed form, which stud engages the strapslot and thereby limits the movement of form 3, it being understood that the latter, due to its weight, would otherwise drop to an indefinite position.

Owing to the fact that the lower form 3 moves in a straight line, its fulcrum connection with form 3 will prevent the latter from moving in an are at its fulcrum point and hence the slotted extension 9 of the hinged member 7 is provided to compensate flor this movement, whereby play of the pint e 8* is open or closed, this play, permitted by the shackle connection, being necessary in order to avoid locking of the intermediate forms at their hinge connection.

As shown in the illustrations, the wood.

companion form 3 will close to a certain eX- tent and in succession form 3 until said.

forms assume the position shown in Fig. 1. Thus the wood stock between each set of forms will first receive a bending pressure adjacent to their fulcrum points, this pressure being distributed at varying distances from said fulcrum throughout the length of the stock until the forms are entirely closed. The bending in this manner will be effected gradually and a positive, even bending pressure is progressively distributed throughout the entire length of the material with the re sult that the fiber of said material is not detrimentally broken or compressed at any one point.

I claim:

1. In a wood bending machine having a fixed form and a reciprocative form, a pair of intermediate forms in toggle connection with the fixed and reciprocative forms, each form being provided with a steam chamber, and a power mechanism connected to the reciprocative form.

2. A wood bending machine comprising a fixed form and a reciprocative form, an intermediate pair of forms having corresponding ends fulcrumed to ends of the fixed and reciprocative forms, the opposite ends of the intermediate forms being in shackle connection one with the other, and a power mechanism connected to the reciprocative form.

In testimony that I claim the foregoing I have hereunto set my hand at Sheboygan in the county of Sheboygan and State of Wisconsin in the presence of two witnesses.

WILLIAM A. KNILANS.

Witnesses H. E. TOENNIES, D. E. BROWN.

within said slot is had as the machine. 

